Metal-melting furnace.



c. D. Mocoun'r.

METAL HBLTING FUBHAOB.

APPLIOA'IIOI YILBD JAI. 4. 1912.

1,046,828. Patented Dec. 1o, 1912.

W/TI'SSES Mw MMM MTORNEYS UNITED STATES PATENT OFFICE.

CYRIL DOUGLAS MQCOURT, 0F STBEATHAM COMMON, LONDON, ENGLAND, ASSIGNOR T0 BADIANT HEATING LIMITED, OF LEEDS, ENGLAND, A BRITISH CORPORATION.

METAL-MELTING FURNAOE.

Bpecloatloii ot Letters Patent.

Patented Dec. 10, 1912.

Application led. January 4, 191B. Serial No. 869,418.

To all whom it may concern:

Be it known that I, CYRIL Dominas Mo- Couiir, a subject of the King of Great Britain, and resident of Braxted Park, Streatham Common, London, S. W., England, have made a certain new and useful Invention Relating to Metal-Melting uriiaces, of which the following is a specification, taken in connection with the accompanying drawing, which forms part of the same.

This invention relates especially to furnaces for melting metals or other material and may comprise a suitable meltin chamber having tie desired number of eatin tubes mounted therein so as to be surrounds by the charge of metal or the like and supply heat thereto, each of these tubes containing granular refractory combustion accelerating material and having an explosive gas-l eous mixture injected thereinto so as to cause its accelerated combustion within the kianular material as more fully described iii the United States patent to Bone, Wilson and McCourt, No. 1,016,261 granted January; 16, 1912, which broadly covers such tu u lar heating units for heating liquids,v

meltin metals, and so forth. By arranging suci heating tubes in substantially vertical position within the meltin chamber the heat from the accelerated com ustion ot the gaseous mixture is transmitted outward through the tubes into the surrounding charge and the hot combustion gases passing upward through additional granular material sup ily further heat thereto which may he similarl transmitted outward to the charge wlii e the hot discharged ases may he used to reheat the material eing fed into the meffing chamber while such material is passing down a suitable charging chute through which the discharge gases pass.

In the accompanying drawing showing in a somewhat diagrammatic way a vertical section through an illustrative form of this invention, the mcltin chamber may be provided with a suitab e lining 2 of material aullccntly refractory to withstand the working temperature of the furnace and preferably having little or no fluxing or other undesirable action in' connection with the charge.

For the melting of copper, brass, alumif num, etc., the chamber lining may be formed of fireclay or the like, while for more infusible charges a still more refractory lining is desirable, such as plumbago, alumina or magnesia compositions in the case of cast iron, steel, and so forth, which may be eiliciently melted under some conditions. The series of heating tubes may be mounted in any desired way so as to traverse the melting chamber and are preferably mounted in a substantially vertical position so as to be surrounded b the charge in the melting chamber an efficiently transmit heat thereto. The heating tubes or separating or inclosing shells 7 which may be of any desired shape and size may for good results he given a cylindrical form and an internal diameter of three or four inches or more and a sufficient number mounted within the chamber to give the desired heating effect. For high temperature work these tubes or inclosing shells 7 may be formed of graphite, alumina or magnesia compositions, although for charges which melt at low temperatures metallic tubes or shells may be used, iron tubes proving hi hly desirable for readily `fusible metal, suc as tin, lead, type meta etc., in which case tlin chamber lining may of course be of metal if desired.

The chamber lining should of course be surrounded with suitable non-conductin material to minimize radiation losses and for high temperature Work this casing may be in the form of a firebrick furnace Wall 1 of the desired thickness which serves to sup ort the chamber. The tubes are each pre erably provided adjacent their lower ends with a suitable plug 18 which may be formed of refractory material and formed with one or more injecting passages 14. 'lhc interior of the tube beyond the plug may be packed with granular combustion accelerat ing material of sufficient refractoriness to withstand the high temperatures developed and preferably of substantially uniform size, such as between about one-half and one inch mesh for a small sized tube. Substantially uniform sized calcined magnesite has proved a highlv desirable combustion accelerating material for high temperature work and porous coarsely crushed llrebrick is suitable for lower temperatures.

The explosive gaseous mixture may be .formed by mixing air and combustible gas in the desired proportions and bringing the `mixture into contact with the combustion .mit the molten char v discharge lug accelerating material4 in an desired wa This may be effected by forcing a previous y formed explosive mixtureof 'air and coal gas, producer gas or other combustible gas or vapor through a su ply pipe 11 communicatinfr with a supp y passage 12 leading to caci one of the heating tubes. The gaseous mixture may .be supplied under a pressure of four to sixteen ounces more or less in order to overcome the resistance of thc granular material in the heating tubes and to inject the mixture through the injecting passages at such s eed as to substantially prevent backfiring under normal operating conditions and effect the highly accelerated combustion of the explosive aseous mixture within the granular comus tion accelerating material.

For high temperature-work it is desirable to form the supply passage with a suitable collecting chamber, such as 17, adjacent the lower end of each heating tube communi-v cating therewith, so that in case of erosion or cracking of any of the tubes so as t adof metal or the like thereto, the metal will enter this collecting chamberl and be discharged therefrom by any suitable automatically releasable plug or device, such, for instance, as the fusible 16 which may be located as shown m t ie rawings atthe bottom of this collecting chamber. In this way the charge in the melting chamber maybe withdrawn in in case of accident, this emergency discharge callin attention to the failure of theheating tu es or connections so that thc regular tapping hole may be opened and the charge also removed in that way. 4A suitable tapping arrangement for high temperature work may comprise a tapping-hole `normally closed by a refractory tappin -valve 9 mounted on a suitable stem 17 wich is preferably given a tubular form so that a cooling current of air or the like may be supplied thereto through the cooling air pipe-(l so as to cool the stem and valve and e discharged through the tapping hole 10 if desired when the valve is closed. This valve stem may of course be protected by a suitable refractory sleeve, such' as 8.

The melting chamber may .havev its to substantially covered with a suitable hoo communicating with the exhaust flue 8 and this hood may be covered to the desired extent with a. suitablel non-conducting casing orlagging 22 to-minimize radiation of heat therefrom. It is-also Vdesirable to provide a suitable charging chute having any desired inclination referablyample to insure `the feed of the merged-material down the same so thatthe--charged material may be heated before entering the-*melting chamber by the hot` discharged gases" from the heating tubes. An linclined charging chute 3 may be used having sufficient slope so that the ingots 4 tend to slide down the same into the melting chamber. A suitable control device is preferably used in connection with this chute so as to control the feed of the charged material to the chamber and this may take the form of the control lever 18 which may be pivoted about the pivot 21 in the hood and have its lower end rojecting through the slot 19 and extenting 1n the form of one or more bars or members into the path of the ingots so as to retard their movement to the desired extent, the handle Q0 allowing this control device to be operated so as to feed the ingots into the melting chamber from time to time. Or in some cases where the heat is sufficientand the control device is located suffieently close to the meltingr chamber the ingots may melt sufficiently to flow down the chute past the discharge device which ma be allowed to remain stationary under sucfi conditions and such an arrangement in which the control device may be in the form of one or more stationary bars atl the bottom of a more ysteeply inclined charging chute, if desired,

may be used in connection with melting furnaces of this character for lead, type metal and similar readily fusible material.

'lhe furnace may be started by separately lighting each one of the heating tubes which may be effected by .o ening the corresponding i niting door 5 in the hood and 1 ittie gaseous mixture at the top o the tu e,^so that it flashes back through the granular material. In this way the granuar material ad'acent the injecting assages becomes heate sufficiently to effbct the highly accelerated surface combustion of the explosivegaseous mixture fed thereto and cause the combustion of the fuel within the granular material to take place with high radiant. efficiency and the development of unusually high temperatures which with somo gaseous mixtures may be as unich as 2000 centigrade even without prehcating or high com )rcssion of the gases. In this way high me ting temperatures are available when required and correspondingly higher efficiencies are secured in melting more fusible material. mitted by radiation from the incandescent refractory, material so as to be transmitted through the tubes or inclosing shells to the surrounding body of molten material which is of course a much more efficient method of heating than by external flame. Under the most efficient operating conditions the combustion of the fuel is practically completed inthe lower part of the tube so that the granular material beyond is heated by thi` ot combustion gases which are thereby considerably cooled before being discharged from the tube and the efficiency is thereby increased. The discharge gases from the The heat is rapidly transies ,can

heating tubes may thus have tempera-turcs approaching that of the molten charge and the this gas tem eratures ma be considerably reduced an a correspon ing saving in the fuel effected by using them in the manner described to reheat the charged material before it is fldd into the melting chamher.

Having described this invention in connection with a number of illustrative forms proportions, materials and arrangements of parts, to the details of which disclosure the invention is not to be limited, what is claimed as new and what is desired to be secured by Letters Patent is set forth in the a )pended claims.

1. in melting furnaces, a melting chamber having refractory lining, a series of substantially vertically arranged heating tubes mounted within said melting chamber, said tubes being formed of highly refractory heat conducting material and being rovided adjacent their lower ends with re ractory plugs formed with injecting passages, granular refractory combustion accelerating material of between about one-half and one inch mesh packed within said tubes, means to force through said injecting assages at a speed greater than the speed of)backfiring an explosive gaseous mixture to cause the highly accelerated surface combustion thereof within said granular material,said means comprising a supply pipe and supply passage communicating wit each heating tube, a collecting chamber provided with an automatically releasable fusible plug communicating with each heating tube to allow the molten material entering said collecting chamber to be dischar ed therefrom, a hood substantially inc osing the top of said melting chamber, an igniting door in said hood to give access to said heating tubes, an exhaust flue communicating with said hood, a char ing chute down which the charged materia tends to feed into said meltin chamber and be simultaneously heated by the hot discharge gases from said tubes and a pivoted control device coperating with said char ing chute to control the feed of the charged material tlicretlirou h.

2. In mellting furnaces a melting chamber having refractory lining, a series of substantially vvertically arran ed heating tubes mounted within said melting chamber, said tubes being formed of refractory heat conducting material and bein provided adjacent their lower ends with refractory plugs formed with injecting passages, granu ar refractory combustion accelerating material within said tubes, means to force through said injectin passages at a speed greater than the spec of backfring an explosive gaseous mixture to cause the highly accelerated surface combustion thereof'within s'adgranular material, a collecting-cham-l ber provided with an automatically releasable fusible plug communicating with cach heating tube to allow the molten material entering said collecting chamber to be discharged tlierefroiii, a hood substantially inclosing the top of said melting chamber, an igniting door in said hood to give access to said heatin tubes, an exhaust fine communicating with said hood, a charging chute down which the charged material tends to feed into said melting chamber and be simultaneously heated by the hot discharge gases from said tubes and apivoted control evice coperating with said charging chute to control the feed of the charged material therethrough.

3. In melting furnaces, a melting chamber, a seiies of substantially vertically ui'- ranged heatin tubes mounted within said melting cham er, said tubes being formed of refractory heat conducting material and being provided adjacent their lower ends with refractory plugs formed with injecting passages, granular refractory combustion acceleratin material within said tubes, means to orce through said injecting passages at a speed greater than the speed of backfiring an explosive gaseous mixture to cause the highly accelerated surface conibustion thereof within said granular mate rial, a collecting chamber provided with an automatically releasable plug communicating with each heating tube to allow the molten material entering said collecting chamber to be discharged therefrom, a hood substantially inclosing the top of said melting chamber, an igniting door in said hood to give access to said heating tubes, an exhaust flue communicatin with said hood, a charging chute down wliich the charged material tends to feed into said melting chamber and be simultaneously heated by the hot discharge gases from said tubes and a control device coperating with said charging chute to control the feed of the charged material therethrough.

4. In meltin furnaces, a melting chamber, a series of heating tubes mounted within said melting chamber, said tubes being formed of refractory heat conducting imiU terial and being provided adjacent. their lower ends with refractory plugs formed with injecting passages, granular refractoijv combustion accelerating material within said tubes, meanfJ to force through said injectingT passages at a speed greater than theI spoed of backfiring an explosive gaseous iiiixtuie to cause the highly accelerated surface conibustion thereof within said granular mate rial, a collecting chamber provided with an automatically releasalle plug communicating with eac i heating tube to allow the inolten material entering said collecting chamber to be discharged therefrom, a hood sub` stantiallyinclosing` the top of said melting chamber, an exhaust flue communicating with said hood, a chargin chute down which the charged material ten s to feed into said melting chamber and be simultaneously heated by the hot discharge gases from said tubesand a control device co erating with said charging chute to contro the feed oft-he charged material therethrough.

5. In furnaces for molten material, a melting chamber, a substantially vertically ar ranged heating tube mounted within said melting chamber, said tube being formed of heat conducting material and being provided adjacent its lower end with a refractory plug formed with an injecting passage, granular refractory combustion accelerating material of between about one-ha1f and one inch mesh within said tube, means to force into contact with said granular material at a speed greater than the speed of backfiring an explosive gaseous mixture to cause the accelerated surface combustion thereof within said heated granular material, a collecting chamber provided with an automaticall releasable plug communicating with said leatingtube to allow the molten material entering said collecting chamber to be discharged therefrom, a hood substantially inclosing the top, of said melting chamber, an exhaust flue communicatin with said hood, a charging chute down wlii tends to feed into said melting c amber and be simultaneously heated-bythe hot discharge gases from said tube and a control device cooperating with said char ing chute to control the feed ofthe charge material therethrough.

6. InY furnaces for molten material a melting chamber, a heating tube mounted within said melting chamber, said tube being formed of heat conducting material, granular refractory combustion accelerating material within said tube, means to force into contact with said granular material at a. speed greater than the speed of backfiring au explosive gaseous mixture to cause the accelerated surface combustion thereof within said heated granular material, a collect-ing chamber provided with anfautomatically releasable plug communicating with said heating tube to-allow the moltenmaterial entering said collecting chamber to be discharged therefrom, a hood substantially inclosng the top of said melting chamber a charging chute down which the charged material tends to feed into said melting chamber and be simultaneously heated by the hot discharge gases from said tube and a control device co erating with said charging chute to contro Ithe feed ofthe charged material therethrou h.

7.y In. furnaces flormolten material a melting chamber, wheat-ing tube mounted vwithin said ,melting chamber, .said tube befing i formed of heat .conducting imaterial,r

ch the char ed materiall granular refractory combustion accelerating material within said tube, means to force into contactA with said granular material at a speed greater than the-speed of backfiring an explosive gaseous mixture to cause the accelerated surface combustion thereof within said heated granular material, and a collecting chamber provided with an automatically releasable plug communicating with said heating tube to allowthe molten material entering said collecting chamber to be discharged therefrom.

8. In furnaces for molten material a melting chamber, a heating tube mounted within said melting chamber, said tube being formed of heat conducting materiall` granular refractory combustion accelerating material within said tube, means to force into contact with said granular material at a speed greater than the speed of backfiring an explosive gaseous mixture to cause the accelerated surface combustion thereof within said heated ranular material, a hood substantially inc osing the top of said melting chamber, a char lng chute down which the charged material tends to feed into said melting chamber and be simultancously heated by the hot discharge gases from said tube and a control device coperating with said charging chute to control the feed of the charged material therethrough.A

9. In furnaces for molten material a melting chamber, a heating tube mounted within said melting chamber, said tube being formed of heat conducting material, granular refractory combustion accelerating material within said tube, means to force into contact with said granular material at a speed greater than the speed of backiring an. explosive gaseous mixture to cause the accelerated surface combustion thereof within said heated granular material, and a charging chute down which the 'charged materia tends to feed into said melting chamber and be simultaneously heated by the-hot discharge ases from said tube.

10. In furnaces or molten material or the like, a furnace chamber, a substantially vcrtically arranged heating unit mounted within said furnace chamber to come in Contact with and supply heat to the charge therein, said heating unit bein formed with a heat conducting inclosing s iell, granular refractory combustion accelerating material within said shell, means to form and feed into contactA with said granular material an explosive gaseous mixture to cause accelerated surface combustion thereof wit-hin said rcfractory material, a hood substantially inclosing the top of said melting chamber, au i niting opcnlng in said hood, an exhaust ue communicating with said hood and chargin chute down which the chargcd materia tends to feed into said melting lits chamber and be simultaneousl heated by the hot discharge gases from said unit.

11. In furnaces for'niolten material or the like, a furnace-chamber, a substantially vertically arranged heating unit mounted within said furnace chamber to come in contact with and supply heat to the charge therein, said heating unit bein formed with a heat conducting iiiclosing shell, granular refractor comtbustion accelerating material within said shell, means toform and feed into contact with said granular material an explosive gaseous mixture to cause accelerated surface combustion thereof within portions of said-refractory material and means to pass the hot gases of saidcombustion throu h additional refractory material in said s ell and absorb heat from said gases.

12. In furnaces for molten material or the like, a furnace chamber, a heating unit mounted within said furnace chamber to come in contactwith and supply heat to the charge therein, said heating unit being formed with a heat conducting inclosing shell, refractory combustion accelerating material within said shell, means to form and feed into contact with said granular material an explosive gaseous mixture to cause accelerated surface combustion thereof Within the first portions of said refractory material and means to pass the hot. gases of said combustion through additional refractory material in said shell and absorb heat from said gases.

13. In furnaces for molten material or the like, a furnace chamber, a heating unit in said furnace chamber to be surrounded by the charge said heating unit being formed with a heat conducting shell, granular refractory combustion accelerating material within said shell, means to form an explosive mixture of combustible gas and of supporter of combustion therefor in substantially the proportions required for complete combustion and feed the same into contact with said refractory combustion accelerating material to effect the accelerated combustion of said explosive gaseous mixture Within said refractor material and transmit heat through sai shell into the surrounding charge, a charging chute communicating with said furnace chamber and means to heat charged material in said chute by the hot gases discharged from said heating unit.

14. In furnaces for molten material or the like, a furnace chamber, a heatiiig unit in said furnace chamber to be surrounded by the char e, said heating unit being formed with a eat conducting shell refractory combustion accelerating material within said shell and A,means to form an explosive mixture of combustible gas and of supporter of combustion therefor substantially the' proportions required for complete combustion and feed the same into contact with said refractory combustion accelerating material to effect the accelerated combustion of said explosive gaseous mixture within said refractory material and transmit heat through said shell into the surrounding charge.

15. In furnaces for heating molten metal or the like, a furnace chamber, a heating unit in said furnace chamber to be surrounded by the charge, said heating unit. being formed with a heat-conducting shell, refractory combustion accelerating material within said shell, means to feed an explosive gaseous mixture of combustible and of supporter of combustion therefor into contact with said combustion accelerating material to effectaccelerated combustion within portions of said refractory material and to transmit. heat through said shell into the surrounding charge.

16. In meltin furnaces, a melting chamber, a substantie ly vertically arranged heating tube in said melting chamber to be surrounded by the charge, said tube being formed of heat conducting material and having inject-ing passages adjacent one end, granular refractory combustion accelerating material Within said tube, means to form an explosive mixture of combustible gas and of supporter of combustion therefor and feed the saine into contact with said granular combustion accelerating` material to effect. the accelerated combustion of said explosive gaseous mixture within said granular material and transmit heat through said tube into the surrounding charge, a charging chute communicating with said melting chamber, means to heat charged material in said chute by the hot gases discharged from said heating tube, and means to control the feed of material through said chute into said melting chamber.

17. In melting furnaces, a melting chainber, a heating tube in said melting chamber to be surrounded by the charge, said tube being formed of heat. conducting material, granular refractory combustion accelerating material within said tube. means to form un explosive mixture of combustible gas and of supporter of combustion therefor and feed the same into contact with said granular combustion accelerating material to effect. the accelerated combustion of said explosive gaseous mixture Within said Granular matcrial and transmit heat t-hrougli said tube into the surrounding charge, a charging chute communicating with said melting chamber, means to heat charged material in said chute by the hot gases discharged from said heat.- ing tube and means to control the feed of material through said chute inte said melting chamber.

18. In meltin furnaces, a melting chamber, a heating tu e in said melting chamber to be surrounded by the charge, said tube being formed of heat conducting material, granular refractory combustion accelerating material within said tube, means to form an explosive mixture of combustible gas and of supporter of combustion therefor and feed the same into contact-with said granular combustion accelerating material to eil'ect the accelerated combustion of said explosive gaseous mix ture within said granular material and transmit heat through said tube into the surrounding charge.

19. In furnaces for heating' moltenv material or the like, a furnace chamber, a heating unit in said furnace chamber to be surrounded by the charge, said heating unitheing formed with a substantially vertical metallic shell within the furnace chamber, refractory combustion accelerating material within said shell, means to feed an explosive gaseous mixture of combustible and of supporter of combustion therefor into contact with said combustion accelerating material to effect accelerated combustion within portions of said refractory material and to pass the hot "ases of said combustion through additionarl portions of said refractory matcrial and to transmit heat through said shell into the surrounding charge and means to heat charged material by the hot gases discharged from said heating unit.

420. In furnaces for heating molten material or the like` a furnace chamber, a heating unit in said furnace chamber to be surrounded by the charge, said heat-ing unit being formed with a tubular shell` refractory combustion accelerating material within said shell, means to feed an' explosive gaseous mixture of combustible and of supporter of combustion therefor into Contact with said combustion accelerating material to effect accelerated combustion of said combustible within portions of said refractory material and to transmit heat through said shell into the surrounding charge.

CYRIL DOUGLAS MCCOURT.

Witnesses:

HARRY L. DUNCAN, J Essie B. KAY.

Copies el this patent may bo'obtalnod for ava cents each, by addressing the Commissioner o! Patents, Washington, D. 0." 

